Puree the peeled bananas together with the oil and sugar in a bowl with a hand blender. Then add the flour, baking powder and salt and stir again. The dough will be quite firm. I added a dash of mineral water, it loosens the mass a little. Now cut the apple into small cubes and fold into the batter.
Finally, fill the dough into the muffin molds and bake in the preheated oven at 150 ° C for about 20-25 minutes.
When I serve them, I like to top the apple and banana muffins with a little cinnamon.